From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77291C7618B for ; Fri, 26 Jul 2019 15:29:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CDA322CB9 for ; Fri, 26 Jul 2019 15:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564154998; bh=pFI+FnKdtCt9/zK/Th1ZUog+lfDJKx/bq8CxistJ1P8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=beATDAfYLmFER2yvX7qP1Qn8Iz6Mtfp+VK3hFWxpNRKK927G+2Aj49mtaGxwuHN8o CRaJoIQ9buLxhN/MhkLlYgRxCIRrGfMYAHQslWP9jIr1Bv1Bg8r2+YwBteJBRNj/OE Ybw7Hs/zo+dIIZFvBvnGLMW58XUSI75EiLhENGH0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388301AbfGZP34 (ORCPT ); Fri, 26 Jul 2019 11:29:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:44642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388942AbfGZP3x (ORCPT ); Fri, 26 Jul 2019 11:29:53 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F288722CBD; Fri, 26 Jul 2019 15:29:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564154992; bh=pFI+FnKdtCt9/zK/Th1ZUog+lfDJKx/bq8CxistJ1P8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nrlcN7DT5zCpUVOjvHR8RMEOk0oS7uEEVhaQy/4vukBNTZohWjlFAI0UjlwOpJ8NN 22/vjABa+jRpWsee2PFKuiXwTOUQU/N5eHhoHpVIv5UJoLn5jKRN6qKkJdSzXXVROc amC5/x7PaAJ2xQ3yyXYb3XRY3xf8ZpeceTGgECi4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikolay Aleksandrov , Martin Weinelt , "David S. Miller" Subject: [PATCH 5.1 29/62] net: bridge: mcast: fix stale ipv6 hdr pointer when handling v6 query Date: Fri, 26 Jul 2019 17:24:41 +0200 Message-Id: <20190726152304.774946256@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190726152301.720139286@linuxfoundation.org> References: <20190726152301.720139286@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Aleksandrov [ Upstream commit 3b26a5d03d35d8f732d75951218983c0f7f68dff ] We get a pointer to the ipv6 hdr in br_ip6_multicast_query but we may call pskb_may_pull afterwards and end up using a stale pointer. So use the header directly, it's just 1 place where it's needed. Fixes: 08b202b67264 ("bridge br_multicast: IPv6 MLD support.") Signed-off-by: Nikolay Aleksandrov Tested-by: Martin Weinelt Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_multicast.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1302,7 +1302,6 @@ static int br_ip6_multicast_query(struct u16 vid) { unsigned int transport_len = ipv6_transport_len(skb); - const struct ipv6hdr *ip6h = ipv6_hdr(skb); struct mld_msg *mld; struct net_bridge_mdb_entry *mp; struct mld2_query *mld2q; @@ -1346,7 +1345,7 @@ static int br_ip6_multicast_query(struct if (is_general_query) { saddr.proto = htons(ETH_P_IPV6); - saddr.u.ip6 = ip6h->saddr; + saddr.u.ip6 = ipv6_hdr(skb)->saddr; br_multicast_query_received(br, port, &br->ip6_other_query, &saddr, max_delay);